As concerns mount with respect to environmental pollution, and waste disposal becomes more difficult and more expensive, there is increasing interest in recycling processes.
PVC itself can be recycled by melting and reprocessing. Flexible PVC products, however, frequently combine PVC with other materials, either other plastics or non-plastic materials, for example with polyester film in exterior automotive body mouldings, textiles in PVC tablecloths and aluminum in packaging film.
The presence of such additional non-PVC components makes recycling of the PVC product very difficult or even virtually impossible.
Methods have been suggested for separating the PVC from the contaminating material. Solvent extraction to dissolve out the PVC followed by filtration to remove the insoluble material is one proposed method.
Cryogenic grinding has also been suggested. The supported PVC material is cooled to a low temperature at which the PVC component becomes brittle. The material is then treated to pulverise the PVC, the non-pulverised contaminating material being separated by screening.
These methods are too expensive to be of general application.
For PVC-containing products in which PVC is not bonded to the other components, physical separation methods such as air separation or vibration separation may be able to remove the major part of these other components, but may leave the PVC insufficiently pure for certain further applications.